Jim, yes I have and they do not work reliably enough for making silver halide coatings. I have two of them.
Originally Posted by jimgalli
I have wrapped the PP with Scotch Tape and coated with it. That gives about a 2 mil gap BTW, but it does not have good quality at all on paper due to swell caused by pushing the puddle ahead of the blade causing buckling.
It is fair with film but has an unreliable gap. Solution use is too great also due to losses out the sides and it makes a real mess with gelatin.
Thank you for your reply. I notice you speak of using this system with Silver Gelatin components.
I did ask a previous question as to if the system would work with an Albumin medium. Is there a difference in viscosity between the two materials that would make a difference in using the tool for Albumin?
As for size, it pretty much sounds as though one's tool selection is going to be based on the size of paper one plans to standardize on using. Kind of like a matched set?
Your class outline does sound interesting, and at least for me, very much approaching rocket science!
By the sounds of your post, I think you're implying that the learning curve is going to be longer than a weeks worth of sessions in the darkroom!
Well P.E., I can say that I'm still interested and perhaps I should wait until the jury returns after some use from different skill level folks.
From my standpoint, I'd be looking at a $500-$600 workshop plus expenses, another $400+ (this figure just as a starting point for conversation) amount for a tool limited in size usage. So all told, I'd be looking at an outlay of roughly a minimum of $1000 or better to be able to hold a tool in my hand that I've not accomplished superior use of, and which requires more trial and error expense to master. Could be a high frustration factor involved here too!
Well you've certainly given us all more information, and I myself certainly appreciate it. I will continue to watch this topic to keep up with your developments.
Ya know Jim, Dave and I are on the way to Montana if you swing down to Vegas first. We could all car pool, and not be bothered if someone wants to stop to take a picture.
Birthday present - one blade, Christmas present second blade, Valentines Day - third blades, Mothers day I could get the rest. "Sigh" I don't have to resort to bribery to do this.
PE ever consider a full plate size blade? 6 1/2 x 8 1/2
Rick, sorry, I didn't give a full answer.
Originally Posted by Rick
Here they are for each paragraph:
The blades work with anything that has viscosity. Therefore any polymer or albumen etc. will work, as long as you give it sufficient time to rest after coating to just set up a tad before moving. This is usually on the order of just 10 - 30 seconds but can be as high as a minute with very low viscosity, dilute gels and polymers. I have never used this for albumen though, so I cannot speak either way, but I have used it for lots of polymers at EK and I've even coated from solvents under a hood. You don't need to just use water if you have the right facilities.
The tool size is based on what size(s) you wish to coat. I would get one the maxiumum size for my work. IDK yet. Give me time. I may change that for the purposes of yield. If you do 4x5 and 8x10, you might get a better yield from 2 blades rather than one larger blade and cutting down the 8x10s. I have to get the yield up on the 8x10s and to do that I need the new redesigned end cap and blade set. Give me a few weeks to test things out at the larger sizes. Also, I don't even have the 11.25" blade yet.
I guarantee that the class will not be rocket science, This will be dump and stir for the darkroom hobbyist. I want to make this as painless as possible and as non-toxic as possible (there will be a few exotic chemicals that no one has ever heard of before (well, no one normal that is - just us abnormal photo engineering types), but nothing like mercury or lead).
The learning curve is not weeks or months, more like days or hours depending. I just don't want people going into the lab and wasting silver. That is just too expensive. I want it to be simple and easy time after time, once you learn the routine. I myself had not done any in years having turned into a desk jockey in my last years at EK, but going back to this was a simple job once I had the right blades. Once I had them, I was turning out 90%+ yield of 4x5s in one night after one afternoon in the light practicing.
Here is a simple test that anyone can perform to test their coating quality for a viscous system:
Dissolve 10 grams of photo grade hard gelatin (Bloom Index 175 or higher) in 84 grams of water at 40 deg C and heat until it becomes free of lumps. Add 2 grams of Red, 2 grams of Blue and 2 grams of Green food color and stir until mixed. Add to this, 6 drops of Kodak Photo-Flo 200 (see below). Use this to paint, pour, puddle push, or otherwise coat your paper, film, plate or whatnot. If you want to harden this, add 20 drops of 10% glyoxal.
You should get an even coating possibly with some small craters caused by the interaction of the food dye with the surfactant (called repellancies and mentioned in another thread on coating sulfonic acid couplers). I have not tweaked the surfactant yet for this test, but it will show up gross unevenness and coating marks. It is a measure of your coating technique.
This test makes a good starting point for judging your coatings for quality. If you get too many coating streaks or repellancies, there is either too much or too little Photo-Flo. Therefore, I suggest that you start at zero with the PF and add it dropwise with stirring and testing the coating mix above to get to the sweet spot. It differes with food dye and with batch of gelatin and with Bloom Index. The value above is an approximate mid-point for my current conditions. This uses a 'new improved' viscous food coloring. My previous batch of food colors was liquid and didn't use the same balance of surfactant. It also coated better.
This test works with any polymer or albumen when coated from water. I don't know how well it works as far as hardening is concerned except with gelatin.
Reflection or transmission density measurements will give you an estimate of uniformity, or just the plain Mark I human eyeball test will do well with this.
The goal is to have the exact same density from side to side and end to end of the sheet with no streaks, scratches or lumps. The repellancies (little round craters) don't count.
Well, to all who responded. I have an answer from the Formulary.
The workshop is scheduled to begin Sunday, June 18th at the Photographer's Formulary in Condon Montana. The tentative workshop outline is as posted above, and we will try to have kits including coating blades for all interested parties. We will include any 'exotic' chemicals, papers for coating and all associated equipment such as stainless steel beakers. (Yes, you have to make and store an emulsion in a light tight container, you didn't think you could store it in the fridge in a glass beaker did you?)
First come, first served. However, the following week is still open on their schedule and if too many register up front early enough before the following week is confirmed with another course, Bud has agreed to consider the possibility of running two sessions back to back rather than turn anyone away.
I am on my way to the machine shop to begin redesign of the larger blades (8.25" and 14.25") and to order the first film coating blade of my design. I am also ordering the first blades for those who have already placed firm orders regardless of price.
Gee, some of you are really anxious, but then the people who did this have already seen the blades and the resultant prints.
I am gratified and thank all of you for your support.
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I'll send an email to Lynn tonight and sign up.
I need to talk with her anyway about workshops she wants me to teach (Photoshop CS2, A Process A Day, and possibly a sensitometry workshop).
The soul never thinks without an image.